| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an intake and exhaust device for a multi-cylinder engine, with which engine output in the whole rotation area can be increased with a simple configuration. <P>SOLUTION: This intake and exhaust device includes: a confluence part connected to the downstream ends of independent exhaust passages 52; and a volume part 62b connected to the downstream end of the confluence part, and formed with a prescribed space thereinside. Each independent exhaust passage 52 and at least an upstream side portion of the confluence part are formed in shape such that negative pressure is generated inside an exhaust port 18 connected to the other adjacent independent exhaust passage 52 by ejector effect. The cross sectional area of the volume part 62b is set to be larger than the cross sectional area of the confluence part such that a positive pressure wave of exhaust emission reaching the volume part 62b reflects to become a negative pressure wave. The length L1 and the cross sectional area of the confluence part are sized such that time when the negative pressure wave generated in the volume part 62b reaches the exhaust port 18 of the other cylinder 12 having the preceding exhaust order to a cylinder 12 from which the exhaust emission that is a generation source of the negative pressure wave is exhausted and an overlap period of the other cylinder 12 overlap. <P>COPYRIGHT: (C)2012,JPO&INPIT |
